Reduction gear unit

Patent metadata

Field	Value
Publication number	US-9541162-B2
Application number	US-201114127357-A
Country	US
Kind code	B2
Filing date	Jun 24, 2011
Priority date	Jun 24, 2011
Publication date	Jan 10, 2017
Grant date	Jan 10, 2017

Abstract

There is provided a reduction gear unit including: a pinion; a bearing that is located on each of both sides of the pinion; a large gear that meshes with the pinion; a gear case that stores therein lubricant oil, and accommodates the pinion and the gear; and pinion bearing caps each of which includes an annular portion, wherein the annular portion extends from outside of the gear case toward inside thereof and parallel to a pinion shaft, and includes an end portion in which an end surface in an extending-direction is provided on a side of the pinion with respect to an extended line of a gear-side end surface of an inner race of the bearing, and an inner peripheral surface of the end portion is formed so that a diameter is decreased from a gear-side end surface of an outer race toward the end surface.

First claim

The invention claimed is:

1. A reduction gear unit comprising:
a pinion that is fixed to a pinion shaft;
a bearing that is located on each of both sides of the pinion;
a large gear that is fixed to an axle, formed with a diameter larger than a diameter of a pinion, and meshes with the pinion;
a gear case that stores therein an amount of lubricant oil, and accommodates therein the pinion and the large gear; and
pinion bearing caps each of which is detachably fixed by a fastener screwed into a side surface of the gear case, and includes an annular portion interposed between the gear case and an outer peripheral surface of an outer race of the bearing and surrounding the outer peripheral surface, wherein
a plate is provided on an end surface of the annular portion, and the plate includes a base portion that is fixed by a fastener screwed from inside of the gear case into the end surface, and an inclined portion that extends from the base portion towards the inside of the gear case to an end surface thereof which is provided on a same side as the pinion with respect to an extended line of a gear-side end surface of an inner race of the bearing,
the bearing includes a tapered roller that includes a large-diameter-side end surface provided on a side of the gear, and
the plate is manufactured from shape-memory alloy, and is formed so that a diameter of an inner peripheral edge of the inclined portion becomes larger at a room temperature, and becomes smaller at a temperature higher than a room temperature, than a diameter of an area where an outer peripheral edge of the large-diameter-side end surface of the tapered roller comes into contact with a raceway surface of the outer race.

2. The reduction gear unit according to claim 1 , wherein a diameter of an inner peripheral edge of the base portion is larger than a diameter of an inner peripheral edge of the end surface.

3. The reduction gear unit according to claim 1 , wherein a diameter of an inner peripheral edge of the base portion is equal to a diameter of an inner peripheral edge of the end surface.

4. The reduction gear unit according to claim 1 , wherein
the inner race rotates integrally with the pinion shaft provided with the pinion, the outer race, and a plurality of the rollers that are arranged rotatably between the inner race and the outer race while maintaining a predetermined spacing to one another in a rotation direction of the inner race,
each of the rollers includes the large-diameter-side end surface that is provided on a side of the gear, and a small-diameter-side end surface that is provided on an opposite side to the side of the gear, and is configured to have a shape tapered from the large-diameter-side end surface toward the small-diameter-side end surface,
the outer race includes a conical raceway surface that is provided on an inner peripheral side, and that comes into contact with an outer peripheral surface of each of the rollers,
the inner race includes
a conical raceway surface that is provided on an outer peripheral side thereof and that comes into contact with the outer peripheral surface of each of the rollers,
a small-diameter-side flange portion that is provided on an opposite side to the pinion with respect to an extended line of the small-diameter-side end surface of each of the rollers, and
a large-diameter-side flange portion that is provided on the side of the pinion with respect to an extended line of the large-diameter-side end surface of each of the rollers, and extends in a direction from the inner race to the outer race to be close to a gear-side end surface of the outer race while enclosing the large-diameter-side end surface of each of the rollers, and forms an opening between the gear-side end surface and the large-diameter-side flange portion, and

in the large-diameter-side flange portion of the inner race, a plurality of through holes that are formed with a predetermined spacing to one another in a rotation direction of the inner race, and that connect from a gear-side end surface of the inner race toward outer peripheral edges of the large-diameter-side end surfaces of the rollers are provided.

5. The reduction gear unit according to claim 4 , wherein when a length from an inner peripheral surface of the inner race to a gear side opening of each of the through holes is represented as L1, and a length from the inner peripheral surface of the inner race to a roller side opening of each of the through holes is represented as L2, each of the through holes has a shape satisfying a relationship expressed as L1<L2.

6. The reduction gear unit according to claim 4 , wherein when a length from an inner peripheral surface of the inner race to a gear side opening of each of the through holes is represented as L1, and a length from the inner peripheral surface of the inner race to a roller side opening of each of the through holes is represented as L2, each of the through holes has a shape satisfying a relationship expressed as L1=L2.

Assignees

• Terasawa Hideo
• Mitsubishi Electric Corp

Inventors

• Terasawa Hideo

Classifications

• F16C2240/40

  Linear dimensions, e.g. length, radius, thickness, gap · CPC title

• F16C33/6666

  from an oil bath in the bearing housing, e.g. by an oil ring or centrifugal disc · CPC title

• F16H57/0423

  Lubricant guiding means mounted or supported on the casing, e.g. shields or baffles for collecting lubricant, tubes or pipes · CPC title

• F16H57/0471

  Bearing · CPC title

• F16C33/58

  Raceways; Race rings · CPC title